The International Programme on Chemical Safety (IPCS) was initiated in 1978 as a cooperative venture of three United Nations agencies: the World Health Organization (WHO), the United Nations Environment Programme (UNEP), and the International Labour Organization (ILO). Managed by WHO, the Programme has as its long-term objectives (1) to evaluate scientifically for international distribution the effects of chemicals on human health and the environment, (2) to develop reliable scientific methods for international use in toxicity testing, epidemiological and clinical studies, and risk assessment, (3) to promote and coordinate scientific cooperation among international in-laboratory testing, epidemiological and clinical studies, research on the biological mechanisms of chemical damage and on dose-response, (4) to develop educational models and programmes for toxicology training by WHO member countries, and (5) to develop models and methods for dealing with in-country and international chemical accidents. In addition, the Programme is charged with management of WHO committees which develop guidelines on exposure limits of chemicals in foods, air and water, and collaborated with the UNEP International Registry of Potentially Toxic Chemicals. Using staff and facilities of Lead and Participating Institutions in cooperating countries the Programme has (1) initiated evaluations of the biological and environmental effects of over 50 chemicals or groups of chemicals; (2) developed collaborative international scientific methodological studies in several priority areas (genotoxicity and carcinogenicity testing, prenatal exposures, neurobehavioural toxicity, environmental epidemiology, reproductive toxicology, immunological response to carcinogens); (3) developed a European model for toxicology training and initiated a comparison of this model with the needs of developing WHO member countries and (4) developed draft model programmes for coping with chemical emergencies, as well as providing a variety of associated guidelines, data sheets, health alerts and other publications. Finally, the Programme has provided neutral ground for the first meeting of Western (OECD, ECE) and an Eastern European socialist (CMEA) international organizations for harmonization and synthesis of global approaches to chemical safety.